Paracervical Vasopressin Injection Compared With Intramyometrial Vasopressin in Abdominal Myomectomy

After the initial physician consultation and investigations have been completed, the
treatment options will be reviewed with the patient. If the patient chooses to proceed with
an abdominal myomectomy, then she will be offered participation in the study.

If she chooses to participate, the patient will undergo routine pre-operative assessments
including either transvaginal ultrasound or pelvic MRI. The pre-operative hemoglobin level
will be measured within at least 2 weeks of the operative procedure.

Randomization to either the vasopressin group or the placebo group will be carried out in
the operating room by assigning each recruited patient a consecutively numbered, sealed
opaque envelope, which will contain the designated treatment as determined by a
computer-generated series of random numbers. The randomization will be performed by an
independent member of the division that is not involved in the study.

At the time of induction of anesthesia, a sealed envelope will be opened by the research
fellow. At the time of induction of anesthesia, the sealed envelope will be opened to reveal
the randomization to only the research fellow. The attending physician will remain blinded.
The research fellow will prepare either the placebo solution or the vasopressin and will be
responsible for performing the paracervical injection. The attending physician will be
responsible for recording the surgeon rate of bleeding, the total ebl, and the total
operating time.

In the both groups, one vial (20 units) of vasopressin will be diluted to 40mL with normal
saline solution. Not more than 16mL (8units) of vasopressin will be used. This dose was
chosen as there is no standard vasopressin dose routinely used. The dose is well below the
maximum amount of vasopressin used, and at a level that few complications have been seen in
the past.

Given it is standard practice for all patients to receive intramyometrial vasopressin
injections, both groups will have the medication ordered and prepared. In the patients
randomized to paracervical vasopressin, 8mL (4mL per side of the cervix) will be injected
using a 22F spinal needle. An additional 8mL (4 units) will be injected in intramyometrial
as this is standard of care in our practice. In the patients randomized to no paracervical
vasopressin, 16mL (8 units) will then be used to inject vasopressin intramyometrial prior to
the myomectomy. This will help determine if the routine of delivery of vasopressin will aid
in decreased blood loss.

The operative case will otherwise proceed in the standard fashion. The total ebl, total
operative time, and myomectomy operative time will all be recorded. The myomectomy operative
time will be recorded from the time of the first incision on the uterus, to complete closure
of any uterine defects.

Inclusion Criteria:

- Age 18-60 years old

- All women who are candidates for abdominal myomectomy and are willing to accept
randomization

Exclusion Criteria:

- Patients unable to consent for the study

- Suspected malignancy

- History of adverse reaction or allergy to vasopressin

- Active cardiovascular or pulmonary disease that would indicate a contraindication to
use of vasopressin